Thermoanalysis of the recrystallization process of melt-homogenized glyceride nanoparticles

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Abstract

The recrystallization behaviour, the time course of polymorphic transitions, and the degree of crystallinity of melthomogenized glyceride nanoparticle dispersions were investigated by differential scanning calorimetry (DSC). The results suggest that these properties of the nanoparticles are different from those of the glyceride bulk materials. Crystallization of the molten emulsified glycerides tripalmitate and hard fat in the dispersed state occurs about 20 °C lower than in the bulk. The melting temperature of the colloidal crystalline particles is lowered as much as 12 °C. Unambiguous interpretation of DSC thermograms is only possible using the information about the crystalline modification of the glyceride nanoparticles obtained by X-ray diffraction studies. The lower degree of crystallinity of the dispersed lipids compared to bulk materials is reflected in the reduced heat of fusion of the glyceride nanoparticles. The polymorphic transitions are accelerated in glyceride nanoparticles as compared to their bulk materials and the effect depends on the emulsifier and its concentration. The crystallinity index of hard fat nanoparticles is lower than that of tripalmitate nanoparticles. Incorporation of the model drug ubidecarenone into different lipid matrices resulted in a decreased crystallinity as well as in a delayed transition of residual α-polymorphic material into the stable β-polymorph. The latter effect was also observed for incorporation of glycerol monostearate. The DSC results can be explained in terms of the colloidal nature of the dispersions and the influence of foreign compounds such as emulsifiers, drugs and impurities.

References (18)

  • K. Westesen et al.

    Int. J. Pharm.

    (1993)
  • F. McNeil-Watson et al.
  • B. Siekmann et al.

    Pharm. Pharmacol. Lett.

    (1992)
  • K. Westesen et al.

    Eur. J. Pharm. Biopharm.

    (1994)
  • N. Garti et al.
    (1988)
  • K. Larsson

    Acta Chem. Scand.

    (1966)
  • K. Thoma et al.

    Pharm. Ind.

    (1983)
  • N. Garti et al.

    J. Am. Oil Chem. Soc.

    (1982)
  • N. Garti et al.

    J. Am. Oil Chem. Soc.

    (1989)
There are more references available in the full text version of this article.

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